this is a packaging related question, but fedora-devel in this case is
probably the better place than fedora-packaging for now (when it comes
to actual implemetaion details fedora-packaging probably is better).

Did anybody in recent times look into packaging thunderbird or firefox
extensions as RPMS in fedora? One of my desktops is a x86_64 machine and
getting a proper enigmail for it sometimes is annoying (¹). Caillion
iirc in the past once said packaging extensions would be possible with
future versions of thunderbird and firefox. Are thunderbird and firefox
2.0 (both in rawhide these days) those future versions or do we have to
wait until 3.0 for proper support? Or are there any workarounds to
somehow make it work now?

3.0. There's no maintainable way to make it work now without querying
RPM in %post and requiring triggers.